Environment Variables in the Config File

You can pull configuration values from environment variables like this:

config.yaml

logLevel: ${{ LOG_LEVEL }}

pageTitle: Olivetin - ${{ DEPLOY_ENV }}

actions:
    ...

While loading the config file, Olivetin will substitute the value of the named environment variable for the token. If the variable is unset, Olivetin will use an empty string as the value and log a warning. This syntax works even for configuration values that aren’t strings, as long as the final string value can be converted to the proper type.

Notes

These variables are read while loading the config file. Changes in the environment won’t be reflected until the config file is reloaded. If you want to read environment variables at execution time in your action’s shell line, make sure to use regular shell syntax, i.e., $FOO rather than ${{ FOO }}. See environment variables for info on using environment variables in your actions.

Using .Env in template replacements

In addition to config-file substitution, OliveTin supports using the process environment inside action templates (e.g. shell, shellAfterCompleted, entity directory titles, and other fields that use Go template syntax). Use {{ .Env.VAR_NAME }} to substitute an environment variable at the time the action is executed.

This is useful when you want a command to depend on the runtime environment (e.g. container or system env) rather than config-load time, or when you need env values in template fields that are not the raw shell command (where you could use $VAR).

Example: use .Env in a shell command

actions:
  - title: Run with deploy env
    shell: /opt/deploy.sh --env {{ .Env.DEPLOY_ENV }} --host {{ .Env.HOSTNAME }}

Example: use .Env in a completion notification

actions:
  - title: Backup
    shell: /opt/backup.sh
    shellAfterCompleted: "apprise -t 'Backup on {{ .Env.HOSTNAME }}' -b '{{ output }}'"

.Env uses the same Go template context as other action variables (e.g. .Arguments, .CurrentEntity, .OliveTin). The map is built from the process environment when OliveTin starts; values are read at template execution time. If a variable is missing, the template engine will report a missing-key error (with missingkey=error), so use defaulting when a variable might be unset, e.g. {{ or .Env.OPTIONAL_VAR "default" }}.

This feature addresses the need to use environment variables in templates without changing the config loader (see GitHub issue #840).